Comparison of emergency department–measured optic nerve sheath diameter according to early neurological outcome in pediatric patients with traumatic brain injury

Early risk stratification in pediatric traumatic brain injury (TBI) is challenging, and readily available bedside markers may help identify children at risk of an adverse clinical course. This study compared emergency department (ED)-measured optic nerve sheath diameter (ONSD) and related ocular ultrasound measurements according to early neurological outcome in children with TBI. This perspective observational study was conducted at Mardani-Azar Pediatric Medical Center, Tabriz, Iran, between January and December 2025. Children younger than 18 years with TBI underwent ocular ultrasonography during their ED evaluation. Bilateral ONSD, eyeball transverse diameter (ETD), and interocular distance (IOD) were measured, and the ONSD/ETD and ONSD/IOD ratios were calculated. Neurological status was assessed 3–5 days after admission using the Glasgow coma scale (GCS). Associations between ultrasound measurements and early clinical outcomes were evaluated using between-group comparisons and receiver operating characteristic (ROC) curve analysis. Among 100 patients, 84 patients (84%) had no CT findings suggestive of raised ICP, whereas 16 patients (16%) had at least one such finding. Mean ONSD was higher in the unfavorable-outcome group than in the favorable-outcome group (5.84 ± 0.67 vs. 4.55 ± 0.41 mm; P < 0.001). The ONSD/ETD and ONSD/IOD ratios were also higher in the unfavorable-outcome group (both P < 0.001), whereas ETD and IOD did not differ significantly. Mean ONSD showed an area under the ROC curve of 0.961 (95% confidence interval [CI], 0.913–0.994) for discriminating the study-defined outcome groups. ED-measured ONSD was associated with early neurological status in this pediatric TBI cohort. These findings suggest that ONSD may warrant further evaluation as an adjunctive bedside risk-stratification marker. Prospective validation using standardized outcome definitions and appropriate adjustment for initial injury severity is needed before its independent prognostic value can be established. Not applicable.